62 F I question

[Bill W.]

my 62 FI [nom] runs great at low rpms, are half throttle .at full trottle it loses power.its much worse above 90 degrees.it almost seems like its running out of gas. It has a new cable,plugs, points,cap and rotor. it runs good in cool weather.I think its the crappy fuel. any ideas

[Iron Duke NCRS #22045]

Re: 62 F I question

Could be a partially clogged fuel filter or a degraded fuel pump that cannot keep up with the engine's fuel demand at high load and revs. I doubt if it's the fuel. Modern fuels generally have lower Reid Vapor Pressure to reduce evaporative emissions, and these fuels are less subject to vapor lock. Modern cars can get away with lower vapor pressure because of good atomization from the injectors. What surprises me is that we don't hear more complaints of hard starting on carbureted cars.

Duke

[Jerry Clark]

Re: 62 F I question

Bill:

It sounds like your Hi Pressure pump may be giving up the ghost. Dale would be the guy to give you a definitive answer.

jer

[Chuck G.]

Re: 62 F I question

Check out the FI drive cable that runs from the distributor to the FI pump on the back of the fuel meter. Often times the "squares" formed into the cable round off, and the cable will spin within the distributor or FI pump end. I've even seen the end of the FI pump round off, allowing the cable to spin at mid to high RPM's. They will work OK at low RPM, but when you put the pedal to the metal it will spin. Easy fix...new cable or rebuild your FI pump. Check it out. Hope this helps. Chuck

[Jerry Clark]

Did ya know

that Cadillac used the identical cable in their power seats , not the housing but the drive cable, I promised I wouldn't tell so keep it to yourself.

jer

[G B.]

Has it ever run right?

Have you ever had this particular engine and FI unit run well at high rpm?

If not, then I would try a richer setting on the fuel meter enrichment lever.

If so, then I would leave the enrichment setting alone and change the fuel filter. I'd also check the initial timing and advance mechanism of the distributor. A stock '62 FI distributor has dual points and no vacuum advance canister. It requires a bunch of initial advance to avoid bogging the engine under full throttle.

The gear pump inside the distributor puts out so much excess pressure that I can't imagine it being the cause of a lean mixture. I've never seen one of these pumps "wear out" the gears. The suggestion to check the condition of the drive cable end is a good one.

[Bill W.]

Re: Has it ever run right?

the drive cable is new. the filter is new. it runs great until the engine gets up to about 190 degrees . or if its over 90 degrees outside. if the outside temp is 65 or 75 degrees you couldnt ask for more,but warm weather forget it

[G B.]

I think I got it now.

Your engine doesn't have any high rpm problem at any water temp on a 60 degree day. On a 90 plus day, when the water temp gets up to 190, you have soft performance at high rpm. Right?

You may be on to something with the modern gasoline theory, but I've never had such a problem with a mixture of Amoco premium and racing gas. I have had more severe heat soak problems with pure pump gas than in the old days. If I don't have any racing gas in the tank and I let the FI soak up heat while parked, it will not idle smoothly for the first 60 seconds after restarting.

You might try 5 gallons of racing gas the next time your tank is low. If that doesn't have any affect on your problem, I would assume that your pump gas is not the culprit.

[John DeGregory]

Re: I think I got it now.

If you are not showing your fuel car try a '57 to '59 one piece plenum to "intake" gasket instead of the four original ones. This gasket is about 1/8" thick and is a great insulator. One problem with using it on a '62 is the plenum leg ports are a bit larger than the gasket. But you should be OK with it. Also make sure your spider copper lines are not touching the plenum and the center of the spider is not to close to the hot plenum bottom. I like Jerry's idea also and agree that the pump is probably not the problem.Also how is the main diaphragm and calibration on the power stop? John

[Bill W.]

Re: I think I got it now.

John... i have no idea. its been on and running sense about 1987 this has been a problem for about 4 years .i just dont drive it when its hot.